Second Bus and First Engine Drop. Need guidance!

[whatdoesthisbuttondo?]

I was really slow and meticulous because I was pretty unfamiliar with how the engine connects to all the systems in general. I used the Ratwell guide and labelled both ends of every connection with tape as well as drew my own diagrams for all the wiring etc. I did a lot of sitting an staring as well, just to absorb as much as I could
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Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[khalimadeath]

[whatdoesthisbuttondo?]

Haha, you are braver than me then.

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Short update followed by some questions...

I removed the tank and I was pretty happy with what I found inside:

So I gave it a quick clean and will try and get at the rust starting in a couple places, and reuse it.

For anyone wondering like I was what the difference in fuel tanks between a 72 and 73 is, it seems to be that the 72 has one extra outlet at the center and back of the tank:

Still degreasing the case...

I am getting closer to putting the top end back together, and want to check that I am not missing anything. Here is what I am planning:


1. Double check ring end gap in cylinders at highest/widest point of cylinder wear (not sure what the maximum allowance is?).

2. Measure the cylinder bores at highest point of wear and match the pistons to the cylinders with the closest fit.

3. Install pistons on rods (arrow to flywheel) and mock up cylinder to case.

4. Check deck height of each piston at TDC (Wilson limits are 0.040-0.080 inches).

5. For final assembly, re-clean everything, install rings on pistons, install pistons in pre-oiled cylinders.

6. Assemble with all gaskets and small amount of sealer at base (none on head end except possibly copper sealant to create carbon seal). Torque heads with set procedure. Do each side in one fell swoop…


I have a few questions before I do any of this though:

The heads were flycut but I don’t know how much material was removed. The mating surface is pretty much flush with the flat surface around it. Do I need to consider this in setting deck height? If so, how?

If I don’t use head gaskets and lap the cylinders to the heads instead, I need a shim or spacer at the bottom end of the cylinder; do I simply put one in that is equal to the removed gasket (uncrushed 0.77mm/ 0.0300 inches)?

Lapping cylinders to heads: there is a lot of horizontal play between the mating surfaces (something like a few mm all directions from the outside of the cylinder). Is this normal?


Do I need to measure/ check compression ratio? Its not mentioned in the Wilson book specifically. Why is it important and how would it effect how I am putting the top end together?

As usual, thanks for any and all wisdom!
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Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[busdaddy]

Sounds like a reasonable plan for the most part.

Ring end gap should be listed in the Bentley as well as piston clearance, don't measure piston side clearance directly at the crown as it's recessed slightly, you want to measure at the skirt in multiple places as well as down from the top past the ring grooves.
You will have to measure the volume of the combustion chambers (cc the heads) and using that number as well as what you discover the deck height to be (with the cylinders directly against the case) use an online calculator to determine what thickness of shims have to go between the case and the cylinders to reach your desired compression ratio.
Side play when lapping isn't a big deal, keep the cylinders perpendicular to the head.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
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Слава Україні!

[udidwht]

Be sure and CC the heads. Not doing so could be disastrous! (valve/s meeting piston)

Who ever did your head work should have cc'd them and wrote those numbers down.
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1972 Westy Hardtop/Type-4 2056cc
96mm Biral AA P/C's~7.8:1CR
Headflow Masters New AMC 42x36mm heads w/Porsche swivel adjusters
71mm Stroke
73 Web Cam w/Web solids
Dual 40mm IDF Webers - LM-2 - 47.5 idles/125 mains/190 air corr./F11 tubes/28mm Vents - Float height 10.45mm/Drop 32mm
Bosch SVDA w/Pertronix module (7.5 initial 28 total @ 3400rpm)
Bosch W8CC plugs
Pertronix Flamethrower 40K coil
S&S 4-1 w/Walker QP 17862
3 rib 002 Trans
185R14 Hankook tires

[whatdoesthisbuttondo?]

OK, lots of little things happening. I will definitely be cc-ing the heads and figuring out deck height, CR etc. Stay tuned for the inevitable questions on that...

I decided to backtrack and opt for some new intake valves as well as the exhaust valves that have already been replaced. I have been reading more and decided that would be a better approach than running the old intake valves which had .001 inch wear on the stem (Wilson says that is half allowable wear). I understand that the engine wears as a unit, with all pieces wearing simultaneously, and it might not make sense to have some brand new parts mixed with worn parts. However, cylinder head and valve related issues come up so often I figure it can't hurt to have a whole new set of valves to match my set of new guides and minimize the risk of valve related failure.

OK, having justified that to myself, I have got the measurements for the piston skirt to cylinder wall side clearance (no ring measurements yet). From largest to smallest:

0.0045"
0.0035"
0.0035"
0.0030"

The Bentley says clearance for new parts should be .0016-.0024", with a wear limit of .008 inches. Unless I am missing something stupidly obvious, the 0.0045" is about halfway to its limit.

There is not much if any scuffing on the pistons which I believe is a good sign.

Would it be an acceptable idea to run with the current piston/ cylinder combo based on the above measurements? This is not a pristine build clearly, and it is only the top end, so I'm trying to find compromise with new and reused parts. I was recommended that if I decide to use them, to put the largest clearance at the hottest cylinder (#3).

Thanks.
_________________
Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[busdaddy]

I'd run that, doesn't sound too bad at all. How do the rings fit in thier grooves?, can you get a feeler gauge in?
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[whatdoesthisbuttondo?]

Yup, checked Ring Side Clearance at four quarters of the piston and the maximum measurements were as follows:

1 Upper: 0.002"
Lower: 0.0015"

2 Upper: 0.0015"
Lower: 0.0015"

3 Upper: 0.002"
Lower: 0.002"

4 Upper: 0.002"
Lower: 0.002"

The gap was widest perpendicular to pin over the skirt, and more snug next to the pin.

Bentley lists the upper ring new gap at 0.002" to 0.003" with a wear limit of 0.005" for upper ring and a new lower compression ring gap at 0.0015" to 0.0027" with a wear limit of 0.004", so I think I'm pretty good.

I did not check the 3-piece oil scraper ring, I assume I assemble it by sandwiching the brass colored corrugated piece between the two flat rings?
_________________
Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[busdaddy]

Sounds good, yes the wiggly thing goes in first and then the thin rings go on top of it on each side, there's a tiny step on the wiggly thing the thin rings sit on..
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[whatdoesthisbuttondo?]

OK everything is back from new machine shop. Had intake valves replaced, a proper 3-angle job done on heads, and got new valve springs as this machinist noticed they were off from each other.

Thanks for the tips guys, they are really concise and have details that matter to someone trying to figure this out.

The consensus on the Samba is to lap the heads to to the cylinders, but I was recently told that if I do this, I will never fully get rid of the carbide from the valve grinding compound, and it will accelerate wear. I was suggested that I check the contact surface, and only if i need to, level the tops of the cylinders using a piece of Emory paper laid out on plate glass on a dead flat surface.

Anyone have any thoughts on one approach vs the other?
_________________
Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[busdaddy]

[whatdoesthisbuttondo?]

OK, I went ahead and lapped the heads this weekend and the results are much better than what I started with.

Here is the sealing surfaces on the heads pre-lapping:

And here is after:

I scrubbed the cylinders and head chambers out after with detergent and hot water, then degreaser and hot water, then wd-40'd them dry (missed one spot and it was insane how fast it started to flash rust, literally like two seconds), then oiled them.

I cc'd the heads as well, and they came out at:

#1 53 ml
#2 52.5 ml
#3 53 ml
#4 54 ml

Allowing for 1 ml or so error, they are all around 53 cc.

Piston dish is 5 cc.

I have to finish checking the deck on the other three cylinders, but #1 was 0.033 inches with the base gasket (I believe its 0.008 inch, so deck of 0.025 without).

Bore is 3.54 inches (90 mm).

Stroke 2.595 (66 mm)

If the other decks are similar, i'm thinking of going with a 0.03 inch shim and no case gasket which would give me 0.055 deck which would get my CR to 7.28:1 if I'm entering things in correctly...

http://www.csgnetwork.com/compcalc.html
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Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[whatdoesthisbuttondo?]

Got the final numbers for deck height.

The smallest is 0.015", the largest is 0.024", so about .009" variation. Average is 0.0195"

There is about .003" larger deck towards the flywheel on cylinders on 1, 3, and 4. I have no idea why, but it is definitely there. I'm measuring at the pin with feeler gauges under a flat edge using 0.0015" and/or .002" for go/no go's.

Going with my average deck height, and with a 0.03" shim I get 0.0495" and a CR of 7.3:1. I calculated for all cylinders with their respective cc's (they vary a tiny bit), and calculated for the min and max deck height for each piston: nothing was far over 7.4:1 nor below 7.2:1, and those are outliers. Pretty much everything hovers around 7.3:1. I'm going to order some 0.03" shims tomorrow and call it a day.

unless...

How do I know if my valves will hit my pistons at the smallest deck of 0.045"? This is the lowest end of the range listed by Wilson, but I also don't have any head gaskets and the chambers were fly cut...

Cheers.
_________________
Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[Tcash]

How do I know if my valves will hit my pistons at the smallest deck of 0.045"?
Put Plato or Tootsie Roll in the valve pockets and assemble engine. Turn the engine over. Remove heads and measure thickness of Plato/ Tootsie and that is your clearance between the valve and piston.
Good luck

[whatdoesthisbuttondo?]

Awesome, thanks!
_________________
Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[whatdoesthisbuttondo?]

Waiting for shims, but got all the tin back from powdercoating, and painted up the de-greased fan shroud:)

_________________
Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[whatdoesthisbuttondo?]

The valve clearance looks good, I put everything together and tightened it down to spec. I used shims that are about half of the thickness I need so I shouldn't have any problems when I get the thicker ones.

here is 3 and 4 after a couple rotations.

How do these valve adjusting screws look? Should I reuse them?

_________________
Orange 1973 Campervan. Rebuilt 1700cc with dual Solex carbs. Pertronix electronic points on stock distributor. Engine rebuild in progress (fall 2023).

[busdaddy]

[Wildthings]

[busdaddy]